1. Field of the Invention
The present invention relates to an accordion fire door. More particularly, the present invention relates to an accordion door that is resistant to fire, heat and/or smoke and is self closing when actuated by exposure to certain conditions of fire, heat and/or smoke. The door may be readily reopened and closed manually after actuation.
2. Description of the Related Art
Fire doors are used as protective devices to localize a fire and/or smoke threat within a structure such as a building. Various types of fire doors are provided to close different kinds of openings generally found in buildings. For example, for a vertical opening having a relatively short width in relation to its height, a vertical fire door is often provided which can close in the direction from top to bottom. For a vertical opening that has a relatively large width or that is irregularly shaped, a horizontal fire door which closes from side to side is appropriate. In the United States, these doors are required to meet certain fire code standards which include, among other things, the doors withstanding certain elevated temperatures and resisting destruction for a specified length of time before being consumed in a fire.
A fire door is intended to serve multiple purposes. First, the door protects a structure from the unimpeded spreading of a fire. In addition, the door can also create a means of egress for occupants trapped behind the door when the door is deployed to its closed position, as well as providing passage for emergency personnel, such as firefighters, to enter the structure for the purpose of evacuating stranded occupants and to fight the fire.
In order to meet these demands a fire door must be resistant to fire. It must also be operable when power to the structure is discontinued since the supply of electrical power is often terminated upon detection of a fire. The door must be capable of being opened and/or possess a means of egress so as to permit trapped occupants sufficient space to exit. In addition, it must be capable of being closed again after being opened to continue to contain the fire.
Folding doors for insulating purposes have been known for some time. U.S. Pat. No. 4,106,544 to Dixon et al. discloses a single accordion shaped door. The door is made of hinged panels which are operated via an electric operating means so that the panels are folded into a vertically stacked arrangement when the door is opened and arranged in a flat position when closed. Theses doors are known to form effective sound, light and air seals. Optionally, they can be equipped with pass through or xe2x80x9cegressxe2x80x9d doors. The electric operating system performs a closing operation that does not require a manual assist. However, these doors are not known to be fire retardant or resistant and rely on electric means to open and close.
Double panel accordion shaped fire doors suitable for providing fire and smoke protection are known. In U.S. Pat. No. 3,509,934 to Smart, a double panel accordion type fire door is disclosed having a hollow core with interconnected parallel door sections and a lead post roller and track assembly for deploying the door. Due to the double panel construction, the door is relatively heavy making it difficult or impossible to move manually, such as to reopen the door to escape a fire after the door has been deployed to a closed position. Furthermore, the complex structure and design result in greater manufacturing costs for both materials and construction.
Some fire doors have a closing and opening actuator which is either battery operated or which uses a battery back-up system. However, in a fire situation, the battery may fail to operate. In addition, a battery must also be monitored and maintained in order to be available when needed. It is therefore desirable to have a fire door that may be readily opened and closed manually without requiring a power assist of any kind.
A single folding shutter fire door made of steel and supported by a scissors-like gate on one side is known (Model no. 1450, sold by Sano Manufacturing, Memphis, Tenn. and manufactured by Shutter Doors, Ltd.). The door is guided and supported by the scissor gate which is attached directly to the door panels. One disadvantage of this door is that it does not satisfy certain fire code requirements due, at least in part, to the structure having the actuator operate on the gate which is exposed to the environment as it is attached to the exterior of one side of the door. The actuating means is thus vulnerable to deformation upon exposure to elevated temperatures and/or fire. A further disadvantage of this door is that due to the gate mechanism being used to actuate closing of the door, excess weight and resistance are added to the door. As a result, once closed, this door is difficult to reopened manually.
U.S. Pat. No. 5,542,460 to McKeon discloses a rolling fire door which includes a self-closing mechanism and a speed regulating means so as to safely deploy the door without the necessity for an auxiliary power supply (i.e., a battery) which may be rendered inoperative in conditions of fire. This door is stored in a rolled condition and is unrolled to close an opening. Due to this configuration, a relatively large area is required adjacent to the door for storing it when not in use. In instances where space is limited, such as elevator shaft entries and the like, these doors are impractical.
There is presently a need for fire doors having sufficiently durable and lightweight construction to permit a person trapped inside a building to be protected from exposure to smoke, heat and fire as well as to exit through the fire door without the assistance of an electrically or battery operated mechanism. It is further necessary for a fire door to allow a firefighter to both reopen the fire door for access to the other side in order to perform fire fighting and rescue activities as well as to close the door once more to again provide fire protection after fire fighting and rescue activities are performed and/or aborted.
Recently promulgated fire regulations now require newly-constructed elevator entryways to be protected with an appropriately rated fire door. These areas typically do not have sufficient space to accommodate a traditional fire door such as a rolling door. In addition, the doors must allow a means of egress. However, the elevator shaft entryway will similarly not accommodate a fire door having an egress door installed in the fire door. There is presently a need for a fire door which occupies minimal space and which can be operated manually to allow a means of egress. This is especially true for protection of elevator entryways.
It is an object of the present invention to overcome the limitations of the prior art.
Another object of the present invention is to provide a fire door that affords adequate protection against fire, heat, and smoke, is not reliant on an exterior power source to be reopened and is easy to reopen after it has been closed.
It is a further object of the present invention to provide a fire door that does not require excessive storage space when not in use.
It is yet a further object of the present invention to provide a door that is lightweight and simple in construction while providing sufficient fire protection.
Briefly stated, the present invention is directed to an accordion fire door including an accordion member having a plurality of interlocking panels formed of a fire retardant or fire proof material, guide means positioned on at least one side of the accordion member for guiding the member during movement between an opened position and a closed position, and releasing means operatively connected to the accordion member for releasing the accordion member in response to a predetermined condition of at least one of heat, fire, smoke, manual initiation and a drive means upon activation of the releasing means, the fire door is deployed to a closed position.
In a preferred embodiment, a plurality of end locks are arranged at interconnected ends of adjacent panels for maintaining panel alignment. In another preferred embodiment, the panels are self hinged along their entire interlocking sides.
According to the invention, a door resistant to fire is made in the form of a single panel accordion door constructed of fire resistant material which, when closed, will prevent fire and smoke on one side of the door from reaching the other side of the door for a period of at least one hour. (i.e., meeting fire tests in compliance with, for example, NFPA 252 standard entitled Standard Methods of Fire Tests of Door Assemblies, 1999 Edition), while at the same time allowing for a means of egress for evacuees and a means of access and/or egress for firefighters.
The fire door of the present invention is capable of providing substantial protection against heat, smoke and/or fire and meeting national and international fire rating code requirements without being constructed with either a double accordion structure or a scissors gate support structure. In a preferred embodiment, the inventive fire door does not require auxiliary power to be deployed but utilizes gravity for this purpose, and can be readily reopened and reset after being deployed.
Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein.